The present invention relates to a matrix type liquid crystal display having orthogonally crossed strip electrodes or the so-called matrix electrode, and more particularly a matrix electrode structure.
A conventional drive technique for a matrix type liquid crystal display, for example, a line sequential drive as shown in FIG. 1 is well known. A main memory 1 stores characters, symbols, patterns or the like and an intelligence signal converter 2 converts data contained in the memory 1 into their associated display patterns. After those patterns are stored line by line into a buffer memory in a column driver 3, respective column electrodes Y.sub.1, Y.sub.2, . . . Y.sub.n are supplied with those patterns. Line electrodes X.sub.1, X.sub.2, . . . X.sub.m crossing the column electrodes, on the other hand, are sequentially enabled through a line driver, thereby displaying information contained in the buffer memory line by line. A control 5 provides an operation control for the line and column driver circuits. A liquid crystal display with a matrix type electrode is labeled 6. With the above mentioned matrix type liquid crystal display, the greater the number of lines, the higher the density of display. Although ensuring a higher degree of display quality, with an increase in the number of lines, a period of time where a signal may be applied during a line interval, that is, a duty ratio is relatively shortened thereby presenting a crosstalk problem. More particularly as far as liquid crystal displays are concerned, a satisfactory contrast of the display is not available because of dull threshold properties and slow responses. There are several attempts to overcome these problems.
(1) the development of liquid crystal material having more definite threshold properties. PA1 (2) a matrix address scheme in the optimum conditions with an extended operating margin (.alpha.=V.sub.on /V.sub.off). PA1 (3) the design of an electrode structure with a seemingly higher resolution.
By way of example, as seen from FIG. 2, two layers of liquid crystal cells 11, 12 are provided with the front cell 11 carrying a predetermined number of column electrodes 14a, 14b, . . . on the front face of its front glass support 13 and a predetermined number of line electrodes 16a, 16b, . . . on its front face of its intermediate glass support 15. The rear cell 12 has a predetermined number of column electrodes 17a, 17b, . . . disposed on the rear face of the intermediate glass support 15 and a predetermined number of line electrodes 19a, 19b, . . . on the rear glass support 18. The line electrodes 16, 19 of the liquid crystal cells 11, 12 should be disposed so as not to overlap with each other, whereas the column electrodes 14, 17 are disposed to overlap with each other. The relationship between the line electrodes 16, 19 are best seen from FIG. 2.
However, the first two methods (1) and (2) cannot realize a remarkable increase in the number of energizable lines while there is no need for modifications in the cell structure. In contradistinction to these, the last method (3) is able to increase the number of energizable lines many times.